<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <button id="btn">按钮</button>
  <script>
    const btn = document.getElementById("btn")
    console.log(btn);
    btn.onclick = function () {
      var arr = [0, 1, 2, 3, 4, 5]
      for (var i = 0; i < arr.length; i++) {
          console.log(i);
      }
    }
    // for (var i = 0; i < p.length; i++) {
    //   let j = i
    //   p[j].onclick = function () {
    //     alert(i)
    //   }
    // }
  </script>
</body>

</html>
